Electric switch.



e. a. THOMAS. ELECTRIC SWITCH. APPUCATION FILED HAY 15 NHL Patented Nov.20. 1917;

Inventor: GEWFGE 8. Tu om 5 UNITED STATES PATENT onruion.

GEORGE B. THOMAS, OF BRIDG-EPORT. CONNECTICUT, ASSIGNOIR/TO THE BRYANTELECTRIC COMPANY, OF BRIDGEPOLRT, CONNECTICUT, A CORPORATION OFCONNECTICUT.

ELECTRIC SWITCH.

Patented Nov. 20, 191 7.

Application filed May 15, 1917. Serial No. 168,658.

and particularly to push button switches of the three-point type, theobject of my invention being to provide a switch of this type of simpleand eiiicient construction which is 'more economical to manufacture thanthose of like general type now on the market.

In the accompanying drawings,

Figure 1 is a plan view of a switch in which my invention is embodied inone form;

Fig. 2 is a broken side elevation thereof; and

Fig. 3 is a schematic representation of the wiring connections andportions of the switch mechanism.

In the embodiment of my invention here shown, the switch comprises acup-shaped insulating body 10 of generally rectangular shape, having inone corner of the switch chamber a standard 11, carrying switch terminal12 and a binding screw 13 for connecting the wire main from a source ofcurrent. At the opposite end of the switch chamber is arranged a secondstandard ll with switch terminal 15 and binding screw 16 for connectionto one branch line. At the same end of the switch chamber with terminals11 but on the, opposite side thereof is a third standard 17, carryingswitch terminal 18 and binding screw 19 for connection to the secondbranch line. Arranged centrally in the chamber is a switch mechanism ofgenerally well-known construction comprising a frame 20 secured to thebody 10. In th1s frame is supported the switch mechanism operated by apair of push buttons 21, jointed at their lower ends to a rocker bar 22mounted on the axis 23. Pivoted below the axis of the rocker bar is theswitch bar 24: mounted on the spindle 25 and subjected to the action ofthe usual coil spring 26. Detent plate 27 engages the,

switch bar 24 and temporarily restrains the latter against motion 1nwell-known manner during the initlal movement of the rocker 22 so thatthe switch bar shifts from one position to the other with a snap action.

legs of the frame between which it works.-

The switch bar 24 comprises a-pair of parallel contact bladesunited bythe bridge piece 28 and preferably integral therewith. One of the bladesis forked to provide a pair of contact arms 29 and 30 arranged at anacute angle to each other, while the opposite blade comprises a singlecontact arm 31 having a predetermined relation to the arm 29 of theforked blade. In one position of the switch, the arm 30 makes contactwith the switch terminal 12 connected to the line wire, while the arm'29 simultaneously engages the terminal 15 leading to one of the branchcircuits, and the blade 31 is in off position. In the second position ofthe switch, the arm 30 of the switch bar is out of contact while the arm29 now engages the line terminal 12 and establishes connection throughthe bridge piece 28 with the terminal 18 leading to the second branchcircuit.

The switch is primarily designed for house lighting and particularly forupstairs and downstairs hall lights. where it is desired to controleither light from the switch.

The connection from the terminal 15, for

instance, may be led to the downstairs hall light, while the connectionfrom the terminal 18 may be led to the upstairs hall light,

through a second switch 31 of like construcposition upon the terminalstandarda fur- I ther simplification of the manufacturing operations.

I claim as my invention 1. A three-point electric switch having a mainterminal and two branch terminals in combination with switchbaroomprising a forked contact blade the arms of which connectalternatively with the main line terminal in the difi'erent positions ofthe switch, while one of said arms connects with one of the branchterminals in one position of the switch and having also a one-armedcontact blade electrically connected to said forked blade and arrangedto engage the second branch line terminal when the twoarmed blade is outof contact with the first mentioned branch line terminal.

2. In a construction such as described in claim 1, the arrangement ofthe branch line terminal which cooperates with the forked contact bladeof the switch bar on the same level in the switch chamber as the mainline terminal.

3. In a construction such as described in claims 1 and 2 the arrangementof the second branch terminal on the same level as ,the first branchterminal and the main line terminal.

In testimony whereof I have signed my name to this specification.

GEORGE B. THOMAS.

